Recently, as apparatuses which record an image onto a recording medium having lower absorbability for ink, inkjet recording apparatuses employing a photo-curable method are used. In said inkjet recording apparatuses employing the photo-curable method, after photo-curable ink jetted from recording heads lands on the surface of a recording medium supported on a platen, the light rays are radiated from a light emitting device onto the ink so that the ink on the recording medium is hardened (See Patent Document 1).
As such photo-curable ink, well known are a radical polymerization system ink and a cationic polymerization system ink. Of these, since the cationic polymerization system ink accumulates the energy of the radiated light rays, said ink has a merit in which it is hardened by an illumination intensity which is lower than that of the radical polymerization system ink, whereby the cationic polymerization system ink has become the ink of choice in the various inkjet recording apparatuses.
However when the cationic polymerization system ink is used, if the distance between the light emitting device and a light receiving member such as a sheet of recording medium is relatively great, the light reflected from the light receiving member enters a jetting surface of the recording head, that is, it enters the surfaces of the an ink-jetting opening, whereby ink adhered on said jetting surfaces is hardened by the reflected light exhibiting the low illumination intensity so that the ink-jetting opening tends to become clogged, which may result in image defects.
In recent years to overcome this matter, on the inkjet recording apparatus using the ink being the cationic polymerization system, a plate member being the same height as said platen, is arranged on a radiating area at the side of the platen, so that the distance between the light receiving member and the light emitting device in said radiating area is shortened, whereby the light rays reflecting toward the ink-jetting surface are reduced.
Patent Document 1: Unexamined Japanese Patent Application Publication No. 2004-338264.